Throttle control for internal combustion engines



Oct. 26, 1937. D. L. WERTZ 2,097,409

THROTTLE CONTROL FdR INTERNAL COMBUSTION ENGINES Filed Dec. 28, 1931 2Sheets-Sheet l INVENTOR ATTORNEY Oct. 26, 1937. D. L. WERTZ 2,097,409

THROTTLE CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Dec. 28, 1931 2Shee'ts-Sheet 2 11v VENTOR ATTORNEY Patented Oct. 26, 1937' UNITEDSTATES THROTTLE CONTROL FOR INTERNAL COMBUSTION ENGINES Daniel L. Wertz,Elmira, N. Y., assignor to Eclipse Machine Company, Elmira,

tion of New York N. 1., a corpora- Application December as, 1931, SerialNo. 583,552

6 Claims.

This invention relates to a throttle control for internal combustionengines and more particularly to an automatic device for causing anengine throttle to be partially opened during the starting operation butto be allowed to move to normal idling position when the engine becomesself-operative.

-In starting internal combustion engines, the throttle is preferablyopened a substantial amount during the cranking operation in order toadmit adequate charges of mixture into the cylinders, and to permitsufflcient throttling to occur at the choke valve when the latter isclosed to obtain the desired temporary enriching of the mixture. It isdesirable, however, that the throttle be moved to its normal idlingposition as soon as the engine starts, in order to prevent racing theengine which is most harmful when the engine is cold and the lubricantsluggish.

A device for automatically controlling an engine throttle as aboveindicated without requiring the attention of the operator is obviouslydesirable, but it is especially advantageous in connection withautomatic starting mechanisms in which the starting operation is broughtabout as a consequence of engine stall, and without the volition of theoperator.

It is an object of the present invention to pro vide a novel automaticdevice for causing an engine throttle to be opened during the startingoperation and to bemoved to its idling position when the engine starts.

Anotherobject is to provide such a device which operates to normallyhold the engine throttle partly open, but allows the same to close toidling position as soon as the engine becomes self-operative.

A further object is to provide such a device in which the vacuum in theintake manifold of the engine caused by self-operation of the engine isrelied upon to overcome the means which normally hold the throttle openwhereby reduction in such vacuum such as might be caused by incipientstalling of the engine will immediately cause the throttle to be opened.

Further objects and advantages will be apparent to those skilled in thisart from the following description taken in connection with theaccompanying drawings in which:

Fig. l is a side elevation partly in section of a preferred embodimentof the invention showing the parts in their normal or idle position;

Fig. 2 is a similar view. showing the parts in the positions assumedwhen the engine is self-operative;

Fig. 3 is a detail in perspective of certain of the operating elementsfor the throttle valve;

Fig. 4 is a side elevation of an engine carburetor showing a secondembodiment of the invention;

Fig. 5 is an enlarged sectional detail thereof showing the parts in thepositions assumed when the engine is not running; and

Fig. 6 is a view similar to Fig. 5 showing the parts in the positions.assumed under normal idling conditions of the engine.

Referring first to Fig. 1 of the drawings, there is shown a carburetor Iof conventional type having a throttle passage 2 in which is located athrottle valve 3 of the usual butterfly type fixed on a cross shaft 4.The shaft 4 has fixedly mounted thereon as by means of a set screw 5 acontrol arm 6 adapted to be actuated by the operator in the usual mannerto control the position of the throttle valve.

The control arm 6 is provided with a projection 1 adapted to engage anadjustable stop screw 8 for limiting the closing movement of thethrottle. According to the present invention, this stop screw. 8 insteadof being mounted, as usual, on a rigid part of the body of thecarburetor is mounted on an arm 9 which is freely pivoted on thethrottle shaft 4 and is provided with a projection ll arranged tocooperate with a stop screw I2 adjustably mounted in a lug l3 formed onthe body of the carburetor.

The stop screws 8 and i2 and the projections l and II are so arrangedthat when said projections engage said stop screws, as shown in Fig. 2,the control arm 6 holds the throttle 3 in position to secure suitableidling operation of the engine.

According to the present invention, means are provided for yieldablyholding the arm 9 with the projection ll spaced from the stop screw l2whereby a substantial opening of the throttle is maintained when theengine is not self-operative. As illustrated in Figs. 1 and 2, thismeans takes the form of a compression spring l4 mounted on a guide rodI5 pivoted at III to the end of the arm 9. This spring normally holdsthe arm 9 in the position illustrated in Fig. 1 whereby the throttle 3is maintained at a predetermined opening suitable for the startingoperation.

Means are provided for overcoming the action of the spring It in theform of a piston I6 mounted on the lower end of the rod l5 within acylinder H the lower end of which is suit-,

ably connected as by a tube l8 to the intake manifold of the engine.-The cylinder I1 is preferably provided with a cover l9 forming a guidefor the piston rod I6 and an abutment for the spring [4.

In operation, during the actuation of the starting mechanism of theengine, the throttle-3 will be maintained partially open as illustratedin Fig. l by the action of the spring l4. The initial self-actuation ofthe engine, however, creates a vacuum in the intake manifold which istransmitted by the tube l8 to the cylinder l1 causing the piston l6 tobe retracted, compressing the spring l4 and bringing the projection llof the arm 3 against the stop screw I 2. The throttle arm 6 is thereuponactuated by the usual throttle return spring (not illustrated) to keepthe throttle valve 3 in its idling position as shown in Fig. 2, exceptwhen moved therefrom by the operator to cause acceleration of the enginein the usual manner.

An additional stop screw 2| mounted in a lug 22 of the carburetor casingis preferably provided to limit the automatic opening action of thethrottle to the most advantageous starting position.

It will be understood that the spring l4 may be so calibrated that thepiston i6 will be moved upward by said spring while there is still acertain amount of vacuum in the intake manifold. By a proper selectionof the strength of said spring, it is possible to cause the throttle tobe partly opened before the engine comes to rest whereby stalling of theengine may be prevented by the automatic opening of the throttle.

It will be understood that any suitable means may be employed forretracting the rod l upon self-actuation of the engine instead of theuse of intake vacuum as above set forth, such as the use of-oilpressure, exhaust pressure, or a solenoid actuated from an engine-drivengenerator.

In the second embodiment of the invention, as illustrated in Figs. 4, 5,and 6, the objects of the invention are accomplished by forming athrottle valve 23 in two halves, one of which indicated at 24 is fixedlymounted on a throttle shaft 25 while the other half 26 is looselymounted on the throttle shaft with freedom for pivotal movement limitedby stops 21 and 28 formed on the throttle part 24. The throttle shaft 25is controlled by suitable manual operating means such as a lever 29, andthe idling position thereof is determined by an adjustable abutment 3|.The abutment 28 is so arranged that when the throttle part 24 is in itsidling position as determined by the adjustable stop 3 I, the throttlepart 26 when in engagement with the stop 28 is also in idling positionas indicated in Fig. 6. A yielding means such as a spring 32 is providedfor biasing the throttle part 26 away from the stop 28 and intoengagement with stop 21 as shown in Fig. 5 in which position thethrottle part 26 is opened a limited amount which is predetermined togive an optimum throttle opening for starting purposes.

The spring 32 is made of such stiffness that it will yield under normalidling intake vacuum and allow the throttle part 26 to rest against theabutment 28. However, when the intake vacuum falls below the normalidling condition, such as in case of incipient stalling, the spring 32will act to open the throttle part 26 and admit additional fuel to. theengine.

In the operation of both embodiments of the invention, during initialstarting the throttle is opened to provide the most advantageousstarting condition but as soon as the eng ne e omes self-operative, theintake vacuum causes the throttle to close to idling position and remainclosed except as operated by the manual controlling means. Should theidling speed be set too low or should the operator apply the load to theengine without sufilciently opening the throttle, thus causing liabilityof stalling the engine, the reduction in the intake vacuum caused by thelowering of the engine speed allows the throttle to open sufliciently toprevent the engine from stalling.

When the engine is stopped, the throttle is allowed to open during thelast few strokes of the pistons whereby a charge of fuel is drawn intothe cylinders which will assist in the subsequent starting of theengine.

Although but two embodiments of the invention have been shown anddescribed in detail, it will be understood that other embodiments arepossible and various changes may be -made in the design and arrangementsof the parts without departing from the spirit of the invention asdefined in the claims appended hereto.

What is claimed is:-

1. Inc. fuel control system for internal combustion engines, a throttleshaft, a throttle valve formed in two parts, one part being fixed onsaid shaft and the other part being pivotally mounted thereon, a stopfor said shaft defining the idling position of the throttle part fixedto said shaft, a stop for the other throttle part limiting its pivotedmovement toward closed position, and means for biasing said pivotedthrottle part away from said stop.

2. In a fuel control system for internal combustion engines, a throttleshaft, a throttle valve formed in two parts, one part being fixed onsaid shaft and the other part being pivotally. mounted thereon, a stopfor said shaft defining the idling position of the throttle part fixedto said shaft, a stop for the other throttle part limiting such pivotalmovement in the opposite direction, and means for yieldably urging saidpivoted throttle part toward said last-named stop.

3. In a carburetor, a mixture passage, a throttle controlling saidpassage, said throttle having a portion of its closing edge movablerelatively to the remainder thereof, and means responsive to suction tocontrol the movement of said movable portion, so that it will movetowards closed position upon an increase in the suction.

4. In an internal combustion engine having a passage through which afuel-air mixture is drawn by engine suction, means to close saidpassage, said means having a part biased to a position precludingmaximum closure, and said part being movable by engine suction to aposition enabling maximum closure.

5. In an internal combustion engine having a passage through which afuel-air mixture is drawn by engine suction, a valve to control the flowof the fuel-air mixture through said passage, a movable member formingpart of said valve, yieldable means tending at all times to move saidmember toward a position permitting increased passage of the fuel-airmixture past the valve, and means adjustably mounting the valve in saidpassage in such a position that engine suction opposes the action ofsaid yieldable means on said movable member to maintain said movablemember in a position permitting maximum closure of the passage as longas engine suction obtains, the yieldable means moving said movablemember toward open position and allowing an increased passage of thetuel-air mixture past the valve upon lessening of the engine suction. 1

6. In an internal combustion engine having a passage through which afuel-air mixture is drawn by engine suction, a butterfly valve to closesaid passage and comprising two complementary sections, a mounting shaftto adjustably mount both sections of the valve, one of said sectionsbeing rigidly attached to the shaft and the other being loose on theshaft to have a limited movement with respect to the shaft and saidother section, said valve being so mounted in the passage that enginesuction tends to hold the movable section in its position affordingmaximum closure, whereby maximum closure or the passage is possible aslong as engine suction obtains, and a spring to move said movablesection toward open position upon lessening oi engine suction.

DANIEL L. WERTZ.

